Short barrel 6.5 - How about a RPM?

orchemo · Friday at 6:20 AM

Winter rains are here, so cabin fever leads to what is next?
Been shooting the 30-06's and 338 Federal the last couple weeks.

Thinking about another 6.5 though. Already have a 6.5 CM and long throated 6.5-284. Both shoot great.

My thought for a short barrel, suppressor ready 6.5 is......

I have a couple Tikka actions around. Grab a 6.5 CM Tikka barrel, rechamber to 6.5 RPM, cut to 18 inches to host a suppressor.

Rationale for the 6.5 RPM is
1. Gives me great velocity in standard long action (30-06 based), even when cutting to 18 inches.
2. Can use a standard 30-06 bolt face.
3. Barrel - ask my local gunsmith to re chamber a factory Tikka barrel which is already 1:8 twist. Take off barrels are relatively cheap and Tikka barrel always shoot well.

Cons: finding right powder to maximize the velocity in an 18 barrel, another cartridge to load for.

Thoughts?

xphunter · Friday at 6:40 AM

There are no cons, other than you will have reduced MV compared to longer barrels
Just use the same powders you would normally use for a standard rifle length barrel of 24-26 inches.
Let's say the MV with 140's is 3000 fps with a 26" barrel.
I would guess 25 to maybe 30 fps loss per inch.
8x25=200, So 2800 fps.
On of the AB loads 140 grain loads had a MV of 3075, so possibly 2875.

With 17 inch 6.5-284's, I have had 140's reloads to 2775, and a tad higher with sustained shooting, so I would expect the upper 28's when loading with a 18" 6.5 RPM

clearwater · Friday at 8:15 AM

Cons: "another cartridge to load for. "

I think you meant Pros:

JD338 · Friday at 1:53 PM

I have a Weatherby Accumark Limited in 6.5 Wby RPM, 24" 8t barrel. Currently using a Leupold VX-3 2.5-8x36mm while waiting for a VX-5HD Gen2 3-15x44mm to arrive.
Ram Shot Grand and Retumbo both shoot well with 140 gr AB, SB and Sierra Game King. The Barnes 127 gr LRX shot very well with Retumbo.
Shot the 140 gr Solid Base with Grand yesterday.
The 100 yard group went .564".